Model S has five USB ports:
To access the front USB ports, open the front compartment of the center console. The front USB ports are located on the rear wall of the compartment:

Rear USB ports are located below the rear touchscreen:

Glovebox USB port:

NOTE: Power is available whenever the vehicle is considered "awake". The vehicle may be awake for many reasons. For example, when using features such as Summon, or when features such as Preconditioning, Keep Climate On, Dog Mode, Camp Mode, or Sentry Mode are enabled. The vehicle is also awake whenever the low voltage battery is being charged or is in use, during high voltage charging, when the vehicle is communicating with the mobile app, etc. Leaving an accessory plugged in does not deplete the low voltage battery.
NOTE: Use USB 3.0 compliant cables to connect a device to a USB port. Using non-compliant cables can result in slower charging, potential connection problems or degraded performance.
NOTE: Do not connect multiple devices using a USB hub. This can prevent connected devices from charging or from being recognized by Media Player, Sentry Mode, Dashcam, etc.
USB Drive Requirements for
Recording Videos
Wireless Phone Chargers
Low Voltage Power Socket
Liftgate Glass (Remove)
Cover - Back Rest - Driver's Seat (Install)